Peer-reviewed veterinary case report
Calvarial hyperostosis causing eye bulging and tearing in young
By Steinmetz, Andrea & Kohl, Stefan·Published in Veterinary ophthalmology·2026·Department of Small Animals, Germany·View original on PubMed →
PetCaseFinder translated the abstract of this peer-reviewed paper into plain English so pet owners can read it. We do not publish original research — every detail traces back to the citation above. How we work →
Original publication title: Suspected Calvarial Hyperostosis Syndrome Causing Different Ophthalmological Signs in Two Young Labrador Retrievers-Case Report.
- Species:
- dog
Plain-English summary
A 9-month-old female Labrador and a 2-year-old male Labrador were both brought in for eye problems. The younger dog had a bulging left eye, while the older dog had watery eye discharge without irritation. After thorough examinations and imaging, both dogs were diagnosed with calvarial hyperostosis syndrome (CHS), which caused abnormal bone growth affecting their eye structures. Fortunately, there was no sign of cancer or infection, and the dogs' conditions were identified early, which is important for treatment.
People also search for: Labrador eye bulging · dog watery eye discharge · calvarial hyperostosis syndrome in dogs
Abstract
OBJECTIVE: To describe calvarial hyperostosis syndrome (CHS) as a potential and unusual cause of exophthalmos or epiphora in young dogs. ANIMALS STUDIED: A nine-month-old female intact (case 1) and a two-year-old male intact Labrador Retriever (case 2). PROCEDURES: Patient history, including previous treatments, was documented. Both cases underwent physical and ophthalmological examinations, computed Tomography (CT), and histopathological analysis. Additional dacryocystorhinography (DCR) was performed in case 2. RESULTS: Lateral exophthalmos of the left eye was the primary clinical sign in case 1. In case 2, serous lacrimal discharge was observed without other signs of ocular irritation. A slightly thickened and firm area distal to the medial canthus of the right eye was also noted. In this case, Jones 1 test on the right side was negative, whereas Jones test 2 revealed increased resistance when flushing the nasolacrimal system. CT imaging in both cases identified solid, smoothly marginated new bone formation. In case 1, this involved the left frontal bone, occipital bone, parietal bone, and temporal bone. In case 2, the new bone formation affected the right lacrimal bone and frontal process of the maxillary bone, leading to encasement and narrowing of the nasolacrimal duct (NLD). Histopathological analysis revealed active bone remodeling with osteoblasts in case 1, while case 2 demonstrated regularly differentiated trabecular lamellar bone with intertrabecular spaces. No evidence of neoplasia or osteomyelitis was observed in either case. Taken together, these findings strongly support a diagnosis of CHS in both cases. CONCLUSIONS: CHS involving flat bones can present as exophthalmos or epiphora and should be considered in the differential diagnoses of these conditions, particularly in young dogs.
Find similar cases for your pet
PetCaseFinder finds other peer-reviewed reports of pets with the same symptoms, plus a plain-English summary of what was tried across them.
Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/39988334/